Gas separation is utilized in many industries and can typically be accomplished by passing a mixture of gases over an adsorbent material in an adsorbent contactor that preferentially adsorbs more readily adsorbed components relative to less readily adsorbed components of the mixture. One type of gas separation technology is swing adsorption. For example, the pressure-swing adsorption (PSA) process adsorbs impurities from a gaseous stream into an adsorbent material in one step and releases the impurities in a subsequent step of a cycle. As another example, the temperature-swing adsorption (TSA) process, which may include PSA process steps, utilizes heating and cooling to enhance the effectiveness of this gas purification.
The use of the swing adsorption hardware may involve large diameter beds to minimize the number of total beds for any given application. However, manufacture and installation of large diameter beds is a difficult engineering problem, which often results in a compromise design at a smaller diameter. As a result multiple beds are often needed to achieve the same process goal. This typically results in greater expense and a larger equipment footprint.
Conventional swing adsorption vessels contain a plurality of individual monolith adsorbent contactors within a cylindrical vessel. The monolith contactors have multiple substantially parallel gas flow channels running along the longitudinal axis of the contactor, with an adsorbent material lining the walls of the open channels. Various engineering problems limit the flow through capacity of such adsorption vessels. For example, larger contactors often provide unintentional and undesirable gaseous stream paths in regions between adjacent contactors. This creates a significant problem because it is difficult to maximize the monoliths process area, while providing a robust mechanical support and hold-down structure aimed at retaining the monoliths in place during the unit operating cycles.
These problems may be further complicated by the swing adsorption process. For example, TSA processes have to overcome substantial challenges in designing equipment to achieve these process needs. Some of the challenges include: (a) rapid cycling of pressure; (b) rapid cycling of temperatures; (c) high area density requirements; and/or (d) forming sufficient microchannels with sufficient adsorbent material. Accordingly, there remains a need in the art for monolith designs that mitigate at least the above-mentioned problems, especially those associated with undesirable gaseous steam paths between contactors.